leetcode--7. Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

click to show spoilers.

Note:

The input is assumed to be a 32-bit signed integer. Your function should return 0 when the reversed integer overflows.

水题，只是要注意判断是否溢出，一开始忘记判断了

class Solution {public:    int reverse(int x) {        int tmp = x, ret = 0;        while(tmp) {            int oldnum = ret;            ret = ret * 10 + tmp % 10;            if((ret - tmp % 10) / 10 != oldnum) return 0;            tmp /= 10;        }        return ret;    }};